package org.aplombh.java.interview.test._231030;

import java.util.Scanner;

public class HJ10_字符个数统计 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String s = in.nextLine();
        int[] chars = new int[128];
        int sum = 0;
        for (int i = 0; i < s.length(); i++) {
            chars[s.charAt(i)]++;
        }
        for (int aChar : chars) {
            if (aChar > 0) sum++;
        }
        System.out.println(sum);
    }
}
